Polychlorinated biphenyls produce regional alterations of dopamine metabolism in rat brain.

Adult male rats were gavaged with a mixture of polychlorinated biphenyls (PCBs; Aroclors 1254 and 1260) at either 500 or 1000 mg/kg body weight. Concentrations of dopamine (DA) and its major metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were determined in caudate nucleus and lateral olfactory tract on postgavage Days 1, 3, 7 and 14. DA and DOPAC concentrations in caudate decreased after exposure to PCBs, as did HVA/DA ratios. DA concentrations in the lateral olfactory tract were unaffected, although DOPAC/DA ratios decreased. These results demonstrate that the mature mammalian nervous system is sensitive to a brief exposure to PCBs and that regional differences exist in the neurochemical sequelae of exposure to PCBs.